Search

In this paper, the Clarke generalized Jacobian of the generalized regularized gap function for a nonmonotone Ky Fan inequality is studied. Then, based on the Clarke generalized Jacobian, we derive a global error bound for the nonmonotone Ky Fan inequalities. Finally, an application is given to provide a descent method. [ABSTRACT FROM AUTHOR]

An “off-the-shelf” fluorescence “turn-on” Mg2+ chemosensor 3,5-dichlorosalicylaldehyde (BCSA) was rationally designed and developed. This proposed sensor works based on Mg2+-induced formation of the 2 : 1 BCSA–Mg2+ complex. The coordination of BCSA to Mg2+ increases its structural rigidity generating a chelation-enhanced fluorescence (CHEF) effect which was confirmed by single crystal XRD studies of the BCSA–Mg2+ complex and TD/DFT calculations. This sensor exhibits high sensitivity and selectivity for the quantitative monitoring of Mg2+ with a wide detection range (0–40 μM), a low detection limit (2.89 × 10−7 mol L−1) and a short response time (＜0.5 s). It can also resist the interference from the other co-existing metal ions, especially Ca2+. Consequently, this fluorescent sensor can be utilized to monitor Mg2+ in real time within actual samples from drinking water. [ABSTRACT FROM AUTHOR]

It is becoming increasingly clear that pollution of fine particles (PM2.5) in China is associated with anthropogenic emissions due to human activities. Source apportionment of PM2.5 plays a significant role in emission control. Although various methods have been developed for source apportionment study, each of them has shortcomings. In particular, local contribution and secondary formation were not well considered in receptor model method. This study established a hybrid source apportionment method, based on combination of a receptor model and a 3-D chemical transport model. Simulated source profile for secondary species are used to constrain the source apportionment result from receptor model. The hybrid method is applied in December 2015 in Handan, a city in Northern China. Sulfate, nitrate, ammonium, black carbon, organic matter and other fine particles are simulated, and totally 32 components are detected during the observation period. The observed PM2.5 is successfully apportioned to regional contributors and local source categories. According to the hybrid source apportionment results, during December 2015, 55% of PM2.5 in Handan is due to local sources, including coal combustion (38%), biofuel (21%), industry (16%), agriculture (10%), vehicle (9%) and dust (6%). This method also has capability to downscale the source contribution to each 12 km grid inside a city. Given potentially large changes of structure of energy, industry, transportation and land use in China in future years, more efforts are needed to clearly identify the latest major sources of PM2.5 and to update the control strategy timely. [ABSTRACT FROM AUTHOR]

AbstractOpen wharves often rely on pile structures for stability, but these can cause local scouring, risking structural integrity and safety. Understanding scour mechanisms induced by propeller jet flow is crucial for effective scour protection, yet research on square piles and double piles is limited. This study presents a series of flume tests to investigate the local scour mechanisms around square piles and circular piles under propeller jet flow. The experiments consist of seven different configurations, including single square piles, double square piles, single circular piles, double circular piles, and a control case without any piles. The main focus of this research is to understand the development and variations of scour depth and scour pit dimensions induced by propeller jet flow. Additionally, the scour mechanisms of square piles are compared with those of circular piles, and the influence of double piles and pile spacing is examined. It can be found that substituting circular piles with square piles in practical engineering will generally lead to an increase in the overall scouring range of the foundation. The horizontal scouring range of double piles is significantly influenced by the pile spacing, resulting in a larger range with increased spacing. However, the variation in pile spacing has minimal impact on the vertical scouring range of the double piles. The shape of piles significantly impacts scour depth in both single and double-pile setups, with square piles resulting in deeper scour. Furthermore, increased pile numbers and narrower spacing contribute to higher scour depths. The results of this study enhance understanding of scour characteristics and offer valuable insights for designing and maintaining pile-supported open wharves, ensuring the safety and durability of waterfront structures through effective scour protection measures. [ABSTRACT FROM AUTHOR]